Ab-453070-1 novel insights of ganglionated plexi ablation for atrial fibrillation: findings from recurrence cases

Epicardial adipose tissue (EAT) containing ganglionated plexi (GP) plays an important role in the presence of atrial fibrillation (AF), but the effect of GP ablation remains controversial. This study aimed to investigate whether the effect of GP ablation on eliminated vagal response and EAT volume persisted after ablation. In 17 patients (70.7± 6.5years, 11 males, 13 persistent AF) who had AF recurrence after 1st pulmonary vein isolation (PVI) and GP ablation, high-frequency stimulation (HFS) at 5 major left atrial (LA)-GP sites (i.e., superior left, inferior left, anterior right, inferior right, and Marshall tract GP) was again performed to detect a vagal response at the 2nd session. The 320-row multidetector CT was performed within 2 weeks before each ablation. The acquired CT images were transferred to a workstation. EAT was defined as -50 to -200 Hounsfield units. The CT-derived EAT volume (around the whole heart and LA) at the 1st session was compared to that at the 2nd session. Despite the elimination of vagal response in all 5 LA-GP sites by GP ablation at the 1st ablation, the percentage of patients in whom a vagal response was elicited was significantly increased in IRGP at 2nd session compared to at 1st session (IRGP; 1st, 42% [7/17] vs. 2nd, 76% [13/17], P=0.009), and there was no significant difference in the other GP sites between initial ablation and the 2nd session (Marshal tract GP; 53% [9/17] vs. 47% [8/17], P=0.79, SLGP; 65% [11/17] vs. 41% [7/17], P=0.16, ILGP; 24% [4/17] vs. 53% [9/17], P=0.06, ARGP; 82% [14/17] vs. 65% [11/17], P=0.27). There was no significant difference in the maximum R-R intervals recorded during HFS between 1st ablation and the 2nd session in all GP sites (Marshal tract GP; 1296 [792-1806] vs. 1020 [772-1294] ms, P=0.12, SLGP; 1064 [760-1560] vs. 1244 [738-1444] ms, P=0.47, ILGP; 1000 [930-1472] vs. 1124 [748-1412] ms, P=0.92, ARGP; 1872 [1128-2880] vs. 1284 [960-1886] ms, P=0.24, IRGP; 1064 [808-1424] vs. 1280 [886-1736] ms, P=0.34). EAT volume increased significantly from the 1st ablation to the 2nd session (whole EAT: 143±78 ml vs. 165±94 ml; P=0.029, LA-EAT: 38± 21 ml vs. 46±28 ml; P=0.007). The elimination of vagal response by GP ablation did not persist and EAT volume increased in AF recurrence cases, suggesting that the effect of GP ablation is transient and GP ablation does not have any favorable effect on EAT in those cases.